Class HtmlStamper

Stamps rich HTML content onto PDF pages with full CSS/JavaScript support. Enables complex layouts, images, tables, and dynamic content for advanced stamping.

// Simple HTML watermark:
var watermark = new HtmlStamper(@"
    <div style='opacity:0.3; font-size:72px; color:red;
                transform:rotate(-45deg)'>
        CONFIDENTIAL
    </div>");
pdf.ApplyStamp(watermark);

// Complex footer with table:
var footer = new HtmlStamper(@"
    <table style='width:100%'>
        <tr>
            <td>{date}</td>
            <td style='text-align:center'>Page {page}</td>
            <td style='text-align:right'>© 2024</td>
        </tr>
    </table>");
pdf.ApplyStamp(footer);

// Logo with external image:
var logo = new HtmlStamper(
    "<img src='logo.png' width='100'/>",
    @"C:\images\");  // Base URL for resources
pdf.ApplyStamp(logo);

Supports full HTML5/CSS3/JavaScript rendering

External resources require HtmlBaseUrl to be set

See: https://ironpdf.com/how-to/stamping/#html-stamper

Inheritance
System.Object
Stamper
HtmlStamper
Inherited Members
Namespace: IronPdf.Editing
Assembly: IronPdf.dll
Syntax
public class HtmlStamper : Stamper

Use HtmlStamper in IronPDF when a C# application works with PDF editing. It represents stamps rich HTML content onto PDF pages with full CSS/JavaScript support.

HtmlStamper matters when an application needs to configure or invoke PDF editing from C# code. The class encapsulates the related options and behavior in a single object that is set up once and reused across render or processing calls. Typical scenarios include batch generation pipelines, templated document workflows, and integration with existing C# document services.

To use HtmlStamper, instantiate or obtain it from the relevant entry point in the IronPDF C# API. Key properties include CssMediaType, HtmlBaseUrl. Assign options or invoke methods on the instance to configure or perform the operation. The stamping covers typical usage in C# end to end.

using IronPdf;

var instance = new HtmlStamper();
var current = instance.CssMediaType;
// Read or assign other properties such as HtmlBaseUrl, CssMediaType

For the broader workflow, see the extract text and images guide in the IronPDF C# documentation. For broader context, the PDF editing portion of the IronPDF C# API contains related types that work with HtmlStamper directly. HtmlStamper instances inherit additional members from Stamper that may be relevant in advanced scenarios. In application code, treat HtmlStamper as a configured object that is constructed once and reused across operations rather than instantiated per call. Configuration is generally idempotent: assigning the same property value twice has the same effect as assigning it once. For diagnostic purposes, inspect the relevant HtmlStamper property after each operation to confirm the configured state. See the constructors, properties, and methods tables below for the complete API surface of HtmlStamper. Application code typically obtains or instantiates a single HtmlStamper and shares it across multiple IronPDF operations rather than recreating it per call.

Constructors

HtmlStamper()

Initializes a new instance of the HtmlStamper class.

Declaration
public HtmlStamper()

HtmlStamper(String)

Initializes a new instance of the HtmlStamper class.

Declaration
public HtmlStamper(string html)
Parameters
Type Name Description
System.String html

The HTML string.

HtmlStamper(String, String)

Initializes a new instance of the HtmlStamper class.

Declaration
public HtmlStamper(string html, string baseUrlString)
Parameters
Type Name Description
System.String html

The HTML string.
System.String baseUrlString

The HTML base URL for which references to external CSS, Javascript and Image files will be relative.

HtmlStamper(String, Uri)

Initializes a new instance of the HtmlStamper class.

Declaration
public HtmlStamper(string html, Uri baseUrl)
Parameters
Type Name Description
System.String html

The HTML string.
System.Uri baseUrl

The HTML base URL for which references to external CSS, Javascript and Image files will be relative.

Properties

CssMediaType

Enables Media="screen" CSS Styles and StyleSheets

Note: By setting AllowScreenCss=false, IronPdf renders Stamp from HTML using CSS for media="print" as if printing a web page in a browser print dialog.

Default value is PdfCssMediaType.Screen.

Declaration
public PdfCssMediaType CssMediaType { get; set; }
Property Value
Type Description
PdfCssMediaType

HtmlBaseUrl

The HTML base URL for which references to external CSS, Javascript and Image files will be relative.

A trick to make references relative to a your project file is 

InnerHtmlBaseUrl = new
Uri(System.Reflection.Assembly.GetEntryAssembly().Location).AbsoluteUri

Declaration
public Uri HtmlBaseUrl { get; set; }
Property Value
Type Description
System.Uri

Inherited members

AntiClockwiseRotateAlignment(HorizontalAlignment, VerticalAlignment, PdfPageRotation)
Html
Opacity
Rotation
HorizontalAlignment
VerticalAlignment
HorizontalOffset
VerticalOffset
MaxWidth
MaxHeight
MinWidth
MinHeight
Hyperlink
Scale
IsStampBehindContent
WaitFor
Timeout
IsStampAnnotation